This record describes multibeam echosounder data collected on RV Investigator voyage IN2016_V01, 'HEOBI: Heard Earth-Ocean-Biosphere interactions' which departed Fremantle on the 8th January 2016 and returned to Hobart on the 27th February 2016.
The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter around Heard and Macdonald islands and between Fremantle and Hobart.
The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz.
Data are stored in *.all raw format for bathymetry and backscatter and in *.wcd format for watercolumn backscatter at the CSIRO. There are 1006 files totalling 22.8 GB of raw data in this dataset.
Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format is corrected for motion and position.
Tide corrections were not applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format and processed bathymetry and backscatter grids in geotiff format.
Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.